print-sll.c revision 356341
1139749Simp/* 2117632Sharti * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997 3117632Sharti * The Regents of the University of California. All rights reserved. 4117632Sharti * 5117632Sharti * Redistribution and use in source and binary forms, with or without 6117632Sharti * modification, are permitted provided that: (1) source code distributions 7117632Sharti * retain the above copyright notice and this paragraph in its entirety, (2) 8117632Sharti * distributions including binary code include the above copyright notice and 9117632Sharti * this paragraph in its entirety in the documentation or other materials 10117632Sharti * provided with the distribution, and (3) all advertising materials mentioning 11117632Sharti * features or use of this software display the following acknowledgement: 12117632Sharti * ``This product includes software developed by the University of California, 13117632Sharti * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 14117632Sharti * the University nor the names of its contributors may be used to endorse 15117632Sharti * or promote products derived from this software without specific prior 16117632Sharti * written permission. 17117632Sharti * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 18117632Sharti * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 19117632Sharti * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 20117632Sharti */ 21117632Sharti 22117632Sharti/* \summary: Linux cooked sockets capture printer */ 23117632Sharti 24117632Sharti#ifdef HAVE_CONFIG_H 25117632Sharti#include "config.h" 26117632Sharti#endif 27117632Sharti 28117632Sharti#include <netdissect-stdinc.h> 29117632Sharti 30117632Sharti#include "netdissect.h" 31117632Sharti#include "addrtoname.h" 32117632Sharti#include "ethertype.h" 33117632Sharti#include "extract.h" 34117632Sharti 35117632Sharti#include "ether.h" 36117632Sharti 37117632Sharti/* 38117632Sharti * For captures on Linux cooked sockets, we construct a fake header 39119418Sobrien * that includes: 40117632Sharti * 41117632Sharti * a 2-byte "packet type" which is one of: 42117632Sharti * 43117632Sharti * LINUX_SLL_HOST packet was sent to us 44117632Sharti * LINUX_SLL_BROADCAST packet was broadcast 45117632Sharti * LINUX_SLL_MULTICAST packet was multicast 46117632Sharti * LINUX_SLL_OTHERHOST packet was sent to somebody else 47117632Sharti * LINUX_SLL_OUTGOING packet was sent *by* us; 48117632Sharti * 49117632Sharti * a 2-byte Ethernet protocol field; 50117632Sharti * 51117632Sharti * a 2-byte link-layer type; 52117632Sharti * 53117632Sharti * a 2-byte link-layer address length; 54117632Sharti * 55117632Sharti * an 8-byte source link-layer address, whose actual length is 56117632Sharti * specified by the previous value. 57117632Sharti * 58117632Sharti * All fields except for the link-layer address are in network byte order. 59117632Sharti * 60117632Sharti * DO NOT change the layout of this structure, or change any of the 61117632Sharti * LINUX_SLL_ values below. If you must change the link-layer header 62117632Sharti * for a "cooked" Linux capture, introduce a new DLT_ type (ask 63117632Sharti * "tcpdump-workers@lists.tcpdump.org" for one, so that you don't give it 64117632Sharti * a value that collides with a value already being used), and use the 65117632Sharti * new header in captures of that type, so that programs that can 66117632Sharti * handle DLT_LINUX_SLL captures will continue to handle them correctly 67117632Sharti * without any change, and so that capture files with different headers 68117632Sharti * can be told apart and programs that read them can dissect the 69117632Sharti * packets in them. 70117632Sharti * 71117632Sharti * This structure, and the #defines below, must be the same in the 72117632Sharti * libpcap and tcpdump versions of "sll.h". 73117632Sharti */ 74117632Sharti 75117632Sharti/* 76117632Sharti * A DLT_LINUX_SLL fake link-layer header. 77117632Sharti */ 78117632Sharti#define SLL_HDR_LEN 16 /* total header length */ 79117632Sharti#define SLL_ADDRLEN 8 /* length of address field */ 80117632Sharti 81117632Shartistruct sll_header { 82117632Sharti uint16_t sll_pkttype; /* packet type */ 83117632Sharti uint16_t sll_hatype; /* link-layer address type */ 84117632Sharti uint16_t sll_halen; /* link-layer address length */ 85117632Sharti uint8_t sll_addr[SLL_ADDRLEN]; /* link-layer address */ 86117632Sharti uint16_t sll_protocol; /* protocol */ 87117632Sharti}; 88117632Sharti 89117632Sharti/* 90117632Sharti * The LINUX_SLL_ values for "sll_pkttype"; these correspond to the 91117632Sharti * PACKET_ values on Linux, but are defined here so that they're 92117632Sharti * available even on systems other than Linux, and so that they 93117632Sharti * don't change even if the PACKET_ values change. 94117632Sharti */ 95117632Sharti#define LINUX_SLL_HOST 0 96117632Sharti#define LINUX_SLL_BROADCAST 1 97117632Sharti#define LINUX_SLL_MULTICAST 2 98117632Sharti#define LINUX_SLL_OTHERHOST 3 99117632Sharti#define LINUX_SLL_OUTGOING 4 100117632Sharti 101117632Sharti/* 102117632Sharti * The LINUX_SLL_ values for "sll_protocol"; these correspond to the 103117632Sharti * ETH_P_ values on Linux, but are defined here so that they're 104117632Sharti * available even on systems other than Linux. We assume, for now, 105117632Sharti * that the ETH_P_ values won't change in Linux; if they do, then: 106117632Sharti * 107117632Sharti * if we don't translate them in "pcap-linux.c", capture files 108117632Sharti * won't necessarily be readable if captured on a system that 109117632Sharti * defines ETH_P_ values that don't match these values; 110117632Sharti * 111117632Sharti * if we do translate them in "pcap-linux.c", that makes life 112117632Sharti * unpleasant for the BPF code generator, as the values you test 113117632Sharti * for in the kernel aren't the values that you test for when 114117632Sharti * reading a capture file, so the fixup code run on BPF programs 115117632Sharti * handed to the kernel ends up having to do more work. 116117632Sharti * 117117632Sharti * Add other values here as necessary, for handling packet types that 118117632Sharti * might show up on non-Ethernet, non-802.x networks. (Not all the ones 119117632Sharti * in the Linux "if_ether.h" will, I suspect, actually show up in 120117632Sharti * captures.) 121117632Sharti */ 122117632Sharti#define LINUX_SLL_P_802_3 0x0001 /* Novell 802.3 frames without 802.2 LLC header */ 123117632Sharti#define LINUX_SLL_P_802_2 0x0004 /* 802.2 frames (not D/I/X Ethernet) */ 124117632Sharti 125117632Shartistatic const struct tok sll_pkttype_values[] = { 126117632Sharti { LINUX_SLL_HOST, "In" }, 127117632Sharti { LINUX_SLL_BROADCAST, "B" }, 128117632Sharti { LINUX_SLL_MULTICAST, "M" }, 129117632Sharti { LINUX_SLL_OTHERHOST, "P" }, 130117632Sharti { LINUX_SLL_OUTGOING, "Out" }, 131117632Sharti { 0, NULL} 132117632Sharti}; 133117632Sharti 134117632Shartistatic inline void 135117632Shartisll_print(netdissect_options *ndo, register const struct sll_header *sllp, u_int length) 136117632Sharti{ 137117632Sharti u_short ether_type; 138117632Sharti 139117632Sharti ND_PRINT((ndo, "%3s ",tok2str(sll_pkttype_values,"?",EXTRACT_16BITS(&sllp->sll_pkttype)))); 140117632Sharti 141117632Sharti /* 142117632Sharti * XXX - check the link-layer address type value? 143117632Sharti * For now, we just assume 6 means Ethernet. 144117632Sharti * XXX - print others as strings of hex? 145117632Sharti */ 146117632Sharti if (EXTRACT_16BITS(&sllp->sll_halen) == 6) 147117632Sharti ND_PRINT((ndo, "%s ", etheraddr_string(ndo, sllp->sll_addr))); 148117632Sharti 149117632Sharti if (!ndo->ndo_qflag) { 150117632Sharti ether_type = EXTRACT_16BITS(&sllp->sll_protocol); 151117632Sharti 152117632Sharti if (ether_type <= ETHERMTU) { 153117632Sharti /* 154117632Sharti * Not an Ethernet type; what type is it? 155117632Sharti */ 156117632Sharti switch (ether_type) { 157117632Sharti 158117632Sharti case LINUX_SLL_P_802_3: 159117632Sharti /* 160117632Sharti * Ethernet_802.3 IPX frame. 161117632Sharti */ 162117632Sharti ND_PRINT((ndo, "802.3")); 163117632Sharti break; 164117632Sharti 165117632Sharti case LINUX_SLL_P_802_2: 166117632Sharti /* 167117632Sharti * 802.2. 168117632Sharti */ 169117632Sharti ND_PRINT((ndo, "802.2")); 170117632Sharti break; 171117632Sharti 172117632Sharti default: 173117632Sharti /* 174117632Sharti * What is it? 175117632Sharti */ 176117632Sharti ND_PRINT((ndo, "ethertype Unknown (0x%04x)", 177117632Sharti ether_type)); 178117632Sharti break; 179117632Sharti } 180117632Sharti } else { 181117632Sharti ND_PRINT((ndo, "ethertype %s (0x%04x)", 182117632Sharti tok2str(ethertype_values, "Unknown", ether_type), 183117632Sharti ether_type)); 184117632Sharti } 185117632Sharti ND_PRINT((ndo, ", length %u: ", length)); 186117632Sharti } 187117632Sharti} 188117632Sharti 189117632Sharti/* 190117632Sharti * This is the top level routine of the printer. 'p' points to the 191117632Sharti * Linux "cooked capture" header of the packet, 'h->ts' is the timestamp, 192117632Sharti * 'h->len' is the length of the packet off the wire, and 'h->caplen' 193117632Sharti * is the number of bytes actually captured. 194117632Sharti */ 195117632Shartiu_int 196117632Shartisll_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p) 197117632Sharti{ 198117632Sharti u_int caplen = h->caplen; 199117632Sharti u_int length = h->len; 200117632Sharti register const struct sll_header *sllp; 201117632Sharti u_short hatype; 202117632Sharti u_short ether_type; 203117632Sharti int llc_hdrlen; 204117632Sharti u_int hdrlen; 205117632Sharti 206117632Sharti if (caplen < SLL_HDR_LEN) { 207117632Sharti /* 208117632Sharti * XXX - this "can't happen" because "pcap-linux.c" always 209117632Sharti * adds this many bytes of header to every packet in a 210117632Sharti * cooked socket capture. 211117632Sharti */ 212117632Sharti ND_PRINT((ndo, "[|sll]")); 213117632Sharti return (caplen); 214117632Sharti } 215117632Sharti 216117632Sharti sllp = (const struct sll_header *)p; 217117632Sharti 218117632Sharti if (ndo->ndo_eflag) 219117632Sharti sll_print(ndo, sllp, length); 220117632Sharti 221117632Sharti /* 222117632Sharti * Go past the cooked-mode header. 223117632Sharti */ 224117632Sharti length -= SLL_HDR_LEN; 225117632Sharti caplen -= SLL_HDR_LEN; 226117632Sharti p += SLL_HDR_LEN; 227117632Sharti hdrlen = SLL_HDR_LEN; 228117632Sharti 229117632Sharti hatype = EXTRACT_16BITS(&sllp->sll_hatype); 230117632Sharti switch (hatype) { 231117632Sharti 232117632Sharti case 803: 233117632Sharti /* 234117632Sharti * This is an packet with a radiotap header; 235117632Sharti * just dissect the payload as such. 236117632Sharti */ 237117632Sharti return (SLL_HDR_LEN + ieee802_11_radio_print(ndo, p, length, caplen)); 238117632Sharti } 239117632Sharti ether_type = EXTRACT_16BITS(&sllp->sll_protocol); 240117632Sharti 241117632Shartirecurse: 242117632Sharti /* 243117632Sharti * Is it (gag) an 802.3 encapsulation, or some non-Ethernet 244117632Sharti * packet type? 245117632Sharti */ 246117632Sharti if (ether_type <= ETHERMTU) { 247117632Sharti /* 248117632Sharti * Yes - what type is it? 249117632Sharti */ 250117632Sharti switch (ether_type) { 251117632Sharti 252117632Sharti case LINUX_SLL_P_802_3: 253117632Sharti /* 254117632Sharti * Ethernet_802.3 IPX frame. 255117632Sharti */ 256117632Sharti ipx_print(ndo, p, length); 257117632Sharti break; 258117632Sharti 259117632Sharti case LINUX_SLL_P_802_2: 260117632Sharti /* 261117632Sharti * 802.2. 262117632Sharti * Try to print the LLC-layer header & higher layers. 263117632Sharti */ 264117632Sharti llc_hdrlen = llc_print(ndo, p, length, caplen, NULL, NULL); 265117632Sharti if (llc_hdrlen < 0) 266117632Sharti goto unknown; /* unknown LLC type */ 267117632Sharti hdrlen += llc_hdrlen; 268117632Sharti break; 269117632Sharti 270117632Sharti default: 271117632Sharti /*FALLTHROUGH*/ 272117632Sharti 273117632Sharti unknown: 274117632Sharti /* packet type not known, print raw packet */ 275117632Sharti if (!ndo->ndo_suppress_default_print) 276117632Sharti ND_DEFAULTPRINT(p, caplen); 277117632Sharti break; 278117632Sharti } 279117632Sharti } else if (ether_type == ETHERTYPE_8021Q) { 280117632Sharti /* 281117632Sharti * Print VLAN information, and then go back and process 282117632Sharti * the enclosed type field. 283117632Sharti */ 284117632Sharti if (caplen < 4) { 285117632Sharti ND_PRINT((ndo, "[|vlan]")); 286117632Sharti return (hdrlen + caplen); 287117632Sharti } 288117632Sharti if (length < 4) { 289117632Sharti ND_PRINT((ndo, "[|vlan]")); 290117632Sharti return (hdrlen + length); 291117632Sharti } 292117632Sharti if (ndo->ndo_eflag) { 293117632Sharti uint16_t tag = EXTRACT_16BITS(p); 294117632Sharti 295117632Sharti ND_PRINT((ndo, "%s, ", ieee8021q_tci_string(tag))); 296117632Sharti } 297117632Sharti 298117632Sharti ether_type = EXTRACT_16BITS(p + 2); 299117632Sharti if (ether_type <= ETHERMTU) 300117632Sharti ether_type = LINUX_SLL_P_802_2; 301117632Sharti if (!ndo->ndo_qflag) { 302117632Sharti ND_PRINT((ndo, "ethertype %s, ", 303117632Sharti tok2str(ethertype_values, "Unknown", ether_type))); 304117632Sharti } 305117632Sharti p += 4; 306117632Sharti length -= 4; 307117632Sharti caplen -= 4; 308117632Sharti hdrlen += 4; 309117632Sharti goto recurse; 310117632Sharti } else { 311117632Sharti if (ethertype_print(ndo, ether_type, p, length, caplen, NULL, NULL) == 0) { 312117632Sharti /* ether_type not known, print raw packet */ 313117632Sharti if (!ndo->ndo_eflag) 314117632Sharti sll_print(ndo, sllp, length + SLL_HDR_LEN); 315117632Sharti if (!ndo->ndo_suppress_default_print) 316117632Sharti ND_DEFAULTPRINT(p, caplen); 317117632Sharti } 318117632Sharti } 319117632Sharti 320117632Sharti return (hdrlen); 321117632Sharti} 322117632Sharti